Organization of the file system
hash algorithm to minimize the number of conflicts. But there is always the
probability of adverse outcomes when a disproportionately large number of file
names hash function places in line to the same result. In this case, the
advantage of using this scheme as compared with the consistent finding almost
lost. Other methods of searching In addition to the methods described in the
file name search directory there are others. An example is the organization of
search directories in the file system, NTFS, with the assistance of so-called B-
tree, which has become a standard way of organizing indexes in database systems
Mounting file systems. As the file must be opened before use, and file system
housed in the section of the disc to be mounted to become accessible system
processes. Mount Function (mount) links the file system from the section on the
disk to the existing hierarchy of the file system function and umount (dismantle)
off of the file system hierarchy. Mount function, thus, allows users to access
data in disk partition as a file system, rather than as a sequence of disk
blocks. Mount procedure is as follows. The user (in this Unix root) announced OS
device name and location in the file structure (empty directory name), where you
want to add file system (mount point). For example, OS Unix systems is a
challenge to mount type: mount (special pathname, directory pathname, options);
where special pathname is the name of a special device files (generally name),
the relevant section of the disk mounted file system directory pathname in the
current directory hierarchy, which will be mounted file system (in other words,
the point of a place or mount), and indicates options if you should mount the
file system, read-only (you will not be performed functions such as write and
creat that produce record in the file system). Then OS verifies that the device
contains a valid file system expected to superblokom format, the list of indices
and index root. Some OS exercise mount automatically as soon as the drive will
meet for the first time (hard drives at boot stage, flexible - when they
inserted in the drive), looking for OS file system on the device. If the file
system is available on the device, it is mounted at the root level, the
conversation to the absolute file name names (pathname) is added to the letter
section. The kernel supports a table mount with each montirovannoy records on
the file system. In each record contains information on the re-mounted devices,
in particular with his clipboard and superblokom root directory, as well as
information on a mount point. To address the potentially dangerous side effects
of the number of references to mount the directory must be equal to 1. Entry
information in the table
Next part
|
O
wlCom Software
